Sacubitril Valsartan Enhances Cardiac Function and Alleviates Myocardial Infarction in Rats through a SUV39H1/SPP1 Axis.

Sacubitril valsartan (lcz696) has been demonstrated as a substitute for angiotensin-converting enzyme inhibitors and angiotensin receptor blockers for the treatment of heart failure. This research is aimed at examining the effects of lcz696 and its target molecules on myocardial infarction (MI). A rat model of MI was induced by left anterior descending artery ligation and treated with lcz696. Lcz696 treatment significantly reduced cardiac injury and heart failure, restored the left ventricular fractional shortening and ejection fraction, and reduced oxidative stress and inflammatory responses in rat myocardium. By analyzing the heart failure-related GSE47495 dataset and performing gene ontology (GO) functional enrichment analysis, we obtained histone lysine methyltransferase SUV39H1 and secreted phosphoprotein 1 (SPP1) as two molecules implicated in the oxidative stress and inflammation processes. An elevation of SUV39H1 whereas a decline of SPP1 were detected in cardiac tissues after lcz696 treatment. Enrichments of SUV39H1 and H3K9me3 at the SPP1 promoter were identified by chromatin immunoprecipitation assay. SUV39H1 catalyzed H3K9me3 modification to suppress the expression of SPP1. Preconditioning of SUV39H1 silencing blocked the protective roles of lcz696, but SPP1 silencing alleviated the myocardial injury. In conclusion, this study demonstrates that lcz696 enhances cardiac function and alleviates MI in rats through a SUV39H1/SPP1 axis.

Circular RNA Foxo3 Relieves Myocardial Ischemia/Reperfusion Injury by Suppressing Autophagy via Inhibiting HMGB1 by Repressing KAT7 in Myocardial Infarction.

INTRODUCTION: Myocardial infarction is coronary artery-related heart disease, and the leading cause of mortality globally. Circular RNAs (circRNAs) are a new type of regulatory RNAs and participate in multiple pathological cardiac progression. METHODS: However, the function of circFoxo3 in MI-induced myocardial injury remains obscure. RESULTS: Significantly, we identified that circFoxo3 was downregulated in the MI rat model and the overexpression of circFoxo3 ameliorated MI-induced cardiac dysfunction and attenuated MI-induced autophagy in rat model. Meanwhile, the overexpression of circFoxo3 repressed oxygen-glucose deprivation (OGD)-induced autophagy, apoptosis, inflammation, and injury of cardiomyocyte in vitro. Mechanically, we identified that the expression of KAT7 was reduced by circFoxo3 overexpression in cardiomyocytes. Meanwhile, the expression of HMGB1 was repressed by the depletion of KAT7 in cardiomyocytes. The enrichment of histone H3 lysine 14 acetylation (H3K14ac) and RNA polymerase II (RNA pol II) on HMGB1 promoter was inhibited by the knockdown of KAT7. Moreover, the overexpression of circFoxo3 suppressed HMGB1 expression and KAT7 overexpression rescued the expression of HMGB1 in cardiomyocytes. The enrichment of KAT7, H3K14ac, and RNA poly II on HMGB1 promoter was decreased by circFoxo3 overexpression, while the overexpression of KAT7 could reverse the effect. The overexpression of KAT7 or HMGB1 could reverse circFoxo3-attenuated cardiomyocyte injury and autophagy in vitro. Thus, we conclude that circular RNA circFoxo3 relieved myocardial ischemia/reperfusion injury by suppressing autophagy via inhibiting HMGB1 by repressing KAT7 in MI. DISCUSSION: Our finding provides new insight into the mechanism by which circFoxo3 regulates MI-related cardiac dysfunction by targeting KAT7/HMGB1 axis.

AdipoRon Alleviates Free Fatty Acid-Induced Myocardial Cell Injury Via Suppressing Nlrp3 Inflammasome Activation.

BACKGROUND: Hypoadiponectinemia is a high risk factor for type 2 diabetes and cardiovascular disease. Although adiponectin is a protective molecule in cardiovascular diseases, it is hampered due to short plasma half-life and high cost of production. This study aimed to investigate whether AdipoRon, a small-molecule adiponectin receptor agonist, alleviated saturated free fatty acids such as palmitic acid (PA)-induced cardiomyocyte injury by suppressing Nlrp3 inflammasome activation. METHODS: Cell viability was used with MTT assay. Cell apoptosis and mitochondria membrane potential were detected by flow cytometry. We also detected the ROS production and colocolization of inflammasome protein with fluorescence and immunofluorescence microscopic analysis, respectively. Then, IL-1ß was detected by Elisa assay and other protein expression was analyzed by Western blot. RESULTS: Our observations demonstrated PA dose-dependently promoted the cell injury, and such high lipotoxicity induced impairment of cardiomyocytes was significantly attenuated by AdipoRon treatment. Moreover, PA markedly activated the first phase of Nlrp3 inflammasome (NF-ƙb) signaling. Notably, the stimulation of PA enhanced ROS production as regulators of Nlrp3 inflammasome activation. In addition, treatment with PA increased the Nlrp3 inflammasome protein expression and complex formation, while AdipoRon abolished it. Lastly, the suppressive effect of AdipoRon to PA-induced cell injury and Nlrp3 inflammasome activation was significantly reversed by Nlrp3 siRNA and pan-caspase inhibitor (z-vad-fmk). CONCLUSION: Taken together, these data suggested that AdipoRon suppressed PA-induced myocardial cell injury by suppressing Nlrp3 inflammasome activation. Thus, AdipoRon might possess potent protective effect in lipotoxicity injury such as obesity leading to cardiac disease.

[Driving force analysis of land use change in the developed area based on Probit regression model: A case study of Nanjing City, China].

Based on the remote sensing image in 1996, 2002 and 2010, with the help of RS and GIS technology, and using the Probit regression model, this paper analyzed the characteristics of land use change in Nanjing City from 1996 to 2010, and the driving factors of land use change. The results showed that the cultivated land and woodland decreased, constructive land, garden plot and grassland continued to increase, and the comprehensive land use change rate was rising since 1996. The results of regression model for cultivated land and woodland change indicated that the change of cultivated land in the years 1996-2002 was mainly affected by the factors of "distance to the nearest rural settlement" and "farmers' population density". However, in the years 2002-2010 it was mainly affected by the factors of "change of per area GDP", "distance to the rural settlement" and "distance to the nearest road". The change of woodland in the years 1996-2002 was mainly affected by the factors of "the elevation" and "distance to the rural settlement". However, in the years 2002-2010 it was mainly affected by the factors of "change of per area GDP", "population density" and "distance to the nearest road". By comparison, the early driving factors of land use change were mainly natural factors, but in recent years, they were mainly social, economic and demographic factors.

Inhibitory effect of midkine-binding peptide on tumor proliferation and migration.

BACKGROUND: To investigate the inhibitory effect of midkine-binding peptides on human umbilical vein endothelial cells (HUVECs) proliferation and angiogenesis of xenograft tumor. METHODS: The midkine-binding peptides were panned by Ph.D.-7(™) Phage Display Peptide Library Kit, and the specific binding activities of positive clones to target protein were examined by phage ELISA. The effect of midkine-binding peptides on proliferation of HUVECs was confirmed by MTT test. The xenograft tumor model was formed in BALB/c mice with the murine hepatocarcinoma cells H22 (H22). Microvessel density (MVD) was analyzed by immunohistochemistry of factor VIII staining. RESULTS: Midkine-binding peptides have the inhibitory effects on tumor angiogenesis, a proliferation assay using human umbilical vein endothelial cells (HUVECs) indicated that particular midkine-binding peptides significantly inhibited the proliferation of the HUVECs. Midkine-binding peptides were also observed to efficiently suppress angiogenesis induced by murine hepatocarcinoma H22 cells in BALB/c nude mice. CONCLUSION: The midkine-binding peptides can inhibit solid tumor growth by retarding the formation of new blood vessels. The results indicate that midkine-binding peptides may represent potent anti-angiogenesis agents in vivo.